Monitoring Spinal Cord Tissue Oxygen in Patients With Acute, Severe Traumatic Spinal Cord Injuries.

Objectives: To determine the feasibility of monitoring tissue oxygen tension from the injury site (psctO2) in patients with acute, severe traumatic spinal cord injuries. Design: We inserted at the injury site a pressure probe, a microdialysis catheter, and an oxygen electrode to monitor for up to a week intraspinal pressure (ISP), spinal cord perfusion pressure (SCPP), tissue glucose, lactate/pyruvate ratio (LPR), and psctO2. We analyzed 2,213 hours of such data. Follow-up was 6-28 months postinjury. Setting: Single-center neurosurgical and neurocritical care units. Subjects: Twenty-six patients with traumatic spinal cord injuries, American spinal injury association Impairment Scale A-C. Probes were inserted within 72 hours of injury. Interventions: Insertion of subarachnoid oxygen electrode (Licox; Integra LifeSciences, Sophia-Antipolis, France), pressure probe, and microdialysis catheter. Measurements and Main Results: psctO2 was significantly influenced by ISP (psctO2 26.7 +/- 0.3 mm Hg at ISP > 10 mmHg vs psctO2 22.7 +/- 0.8 mm Hg at ISP = 90 mm Hg), tissue glucose (psctO2 26.8 +/- 0.4 mm Hg at glucose = 6 mM), tissue LPR (psctO2 25.3 +/- 0.4 mm Hg at LPR > 30 vs psctO2 31.3 +/- 0.3 mm Hg at LPR = 39[degrees]C). Tissue hypoxia also occurred independent of these factors. Increasing the FIO2 by 0.48 increases psctO2 by 71.8% above baseline within 8.4 minutes. In patients with motor-incomplete injuries, fluctuations in psctO2 correlated with fluctuations in limb motor score. The injured cord spent 11% (39%) hours at psctO2 less than 5 mm Hg (< 20 mm Hg) in patients with motor-complete outcomes, compared with 1% (30%) hours at psctO2 less than 5 mm Hg (< 20 mm Hg) in patients with motor-incomplete outcomes. Complications were cerebrospinal fluid leak (5/26) and wound infection (1/26). Conclusions: This study lays the foundation for measuring and altering spinal cord oxygen at the injury site. Future studies are required to investigate whether this is an effective new therapy